Bond pad rerouting element and stacked semiconductor device assemblies including the rerouting element

ABSTRACT

A rerouting element for a semiconductor device includes a dielectric film that carries conductive vias, conductive elements, and contact pads. The conductive vias are positioned at locations that correspond to the locations of bond pads of a semiconductor device with which the rerouting element is to be used. The conductive elements, which communicate with corresponding conductive vias, reroute the bond pad locations to corresponding contact pad locations adjacent to one peripheral edge or two adjacent peripheral edges of the rerouted semiconductor device. The rerouting element is particularly useful for rerouting centrally located bond pads of a semiconductor device, as well as for rerouting the peripheral locations of bond pads of a semiconductor device to one or two adjacent peripheral edges thereof. In addition, methods for designing and using rerouting elements are disclosed. Semiconductor device assemblies including one or more rerouting elements that provide contacts adjacent to one or two adjacent peripheral edges of a semiconductor die are also disclosed, as are semiconductor device assemblies in which contacts adjacent to two or more peripheral edges of a lower semiconductor device are exposed laterally beyond peripheral edges of an upper semiconductor device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/646,966,filed Aug. 22, 2003, now U.S. Pat. No. 6,987,325, issued Jan. 17, 2006,which is a divisional of application Ser. No. 10/118,366, filed Apr. 8,2002, pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to elements that reroute thelocations of bond pads on semiconductor devices and, more specifically,to rerouting elements that are configured to be secured to the activesurfaces of fabricated semiconductor devices to reroute the bond padlocations thereof. In addition, the present invention relates to methodsfor designing rerouting elements and to rerouting methods. The presentinvention also relates to multi-chip modules with semiconductor devicesin stacked arrangement and including one or more of the reroutedsemiconductor devices, as well as to methods for forming and packagingsuch assemblies.

2. Background of Related Art

In order to conserve the amount of surface area, or “real estate,”consumed on a carrier substrate, such as a circuit board, bysemiconductor devices connected thereto, various types of increaseddensity packages have been developed. Among these various types ofpackages is the so-called “multi-chip module” (MCM). Some types ofmulti-chip modules include assemblies of semiconductor devices that arestacked one on top of another. The amount of surface area on a carriersubstrate that may be saved by stacking semiconductor devices is readilyapparent—a stack of semiconductor devices consumes roughly the sameamount of real estate on a carrier substrate as a single, horizontallyoriented semiconductor device or semiconductor device package.

Due to the disparity in processes that are used to form different typesof semiconductor devices (e.g., the number and order of various processsteps), the incorporation of different types of functionality into asingle semiconductor device has proven very difficult to actually reduceto practice. Even in cases where semiconductor devices that carry outmultiple functions can be fabricated, multi-chip modules that includesemiconductor devices with differing functions (e.g., memory, processingcapabilities, etc.) are often much more desirable since the separatesemiconductor devices may be fabricated independently and laterassembled with one another much more quickly and cost-effectively (e.g.,lower production costs due to higher volumes and lower failure rates).

Multi-chip modules may also contain a number of semiconductor devicesthat perform the same function, effectively combining the functionalityof all of the semiconductor devices thereof into a single package.

An example of a conventional, stacked multi-chip module includes acarrier substrate, a first, larger semiconductor device secured to thecarrier substrate, and a second, smaller semiconductor device positionedover and secured to the first semiconductor device. Any suitableadhesive may be used to secure the semiconductor devices to one another.The second semiconductor device does not overlie bond pads of the firstsemiconductor device and, thus, the second semiconductor device does notcover bond wires that electrically connect bond pads of the firstsemiconductor device to corresponding contacts or terminal pads of thecarrier substrate. Such a multi-chip module is disclosed and illustratedin U.S. Pat. No. 6,212,767, issued to Tandy on Apr. 10, 2001(hereinafter “the '767 patent”). Due to the use of bond wires to formelectrical connections between bond pads and corresponding terminalpads, this type of stacked multi-chip module has been limited to usewith semiconductor devices that include peripherally located bond pads.

U.S. Pat. No. 5,323,060, issued to Fogal et al. on Jun. 21, 1994(hereinafter “the '060 patent”) shows one example where dice of the samesize are stacked on top of one another over a circuit board. Bondingwires are connected from the bond pads of each die to correspondingterminal pads on the circuit board. In order to provide clearance forthe bond wires that electrically connect bond pads and correspondingterminal pads, however, adjacent semiconductor devices must be spacedapart from one another a significant distance.

Stacked multi-chip modules of other configurations have also beendeveloped. For example, it is known that stacked multi-chip modules mayinclude large semiconductor devices positioned over smallersemiconductor devices and that adjacent semiconductor devices may bestaggered relative to one another or have different orientations.

Different electrical connection technologies, including wire bonding,tape-automated bonding (“TAB”), and controlled-collapse chip connection(“C-4”), which results in a so-called flip-chip arrangement, are but afew of the ways in which discrete conductive elements may be formed instacked multi-chip modules. Different electrical connection technologieshave also been used in single multi-chip modules, with the bond pads ofone semiconductor device being electrically connected to correspondingcontact areas of a carrier substrate of the multi-chip module with adifferent type of discrete conductive element than that used to formelectrical connections between the bond pads of another semiconductordevice and their corresponding contact areas of the carrier substrate.

Many semiconductor devices include bond pads that are arranged atcentral locations on an active surface thereof. Examples includesemiconductor devices that are configured for use with leads-over-chip(LOC) type lead frames, in which the bond pads are arrangedsubstantially linearly along the centers thereof, as well assemiconductor devices with bond pads disposed in an “I” arrangement.While it may be desirable to use such semiconductor devices in stackedmulti-chip modules, the central bond pad placements thereof do notreadily facilitate the use of bond wires or other laterally extendingdiscrete conductive elements to electrically connect the bond pads withtheir corresponding terminal pads of a circuit board that underlies thesemiconductor device stack.

Accordingly, there are needs for apparatus and methods that facilitatethe use of semiconductor devices with centrally located bond pads instacked multi-chip modules. There are also needs for apparatus andmethods for reducing the heights of stacked multi-chip modules thatinclude semiconductor devices with peripherally located bond pads.

SUMMARY OF THE INVENTION

A rerouting element incorporating teachings of the present inventionincludes a substantially planar member, referred to herein as a basesubstrate, with opposed top and bottom surfaces. The base substrate ofthe rerouting element carries electrically conductive vias, or contacts,that are exposed to the bottom surface thereof and arranged to mirror afootprint of one or more bond pads on a surface of a semiconductordevice, such as an LOC type semiconductor device or a semiconductordevice with peripherally arranged bond pads, to which the reroutingelement is to be secured.

Each electrically conductive via of the rerouting element communicateswith a corresponding conductive trace thereof. The conductive traces ofthe rerouting element may be carried internally within the substantiallyplanar member, externally on the top or bottom surface thereof, or insome combination thereof. Each conductive trace leads to a correspondingreroute location on the base substrate, at which a contact pad ispositioned. Upon assembly of the rerouting element with a semiconductordevice complementary thereto, the contact pads of the rerouting elementwill be located at desired positions relative to an active surface ofthe semiconductor device.

A rerouted semiconductor device according to the present inventionincludes a semiconductor device with one or more bond pads on a surfacethereof and a rerouting element with electrically conductive vias thatare positioned to align with corresponding bond pads of thesemiconductor device. The rerouting element is positioned over a bondpad-bearing surface of the semiconductor device with electricallyconductive vias of the rerouting element and corresponding bond pads ofthe semiconductor device in alignment and electrically communicatingwith one another. The rerouting element is secured to the bondpad-bearing surface of the semiconductor device with the conductivetraces and contact pads of the rerouting element being electricallyisolated from underlying structures of the semiconductor device.

When used in an assembly of stacked semiconductor devices, the reroutedsemiconductor device may facilitate the positioning of one or more othersemiconductor devices over a central region (i.e., the locations ofsubstantially centrally positioned bond pads) thereof. In addition, arerouted semiconductor device that incorporates teachings of the presentinvention may facilitate the use of shorter discrete conductive elementsto connect rerouted bond pads to corresponding contact areas of acarrier substrate than would otherwise be required to connect morecentrally located bond pads to their corresponding contact areas.

Alternatively, the use of a rerouting element that incorporatesteachings of the present invention may facilitate the use ofsemiconductor devices with peripherally located bond pads in assemblieswhich include semiconductor devices that are stacked in staggeredarrangement relative to one another.

A semiconductor device assembly incorporating teachings of the presentinvention includes a first, rerouted semiconductor device and a secondsemiconductor device positioned over the first, rerouted semiconductordevice. When the first and second semiconductor devices are assembledwith one another, the rerouted bond pads of the first, reroutedsemiconductor device may be exposed beyond an outer periphery of thesecond semiconductor device. Accordingly, the second semiconductordevice may have smaller dimensions than those of the first semiconductordevice. Alternatively, the lateral position of the second semiconductordevice may be staggered relative to the position of the first, reroutedsemiconductor device, or only partially superimposed over the firstsemiconductor device. Such a semiconductor device assembly may alsoinclude a carrier substrate, such as a circuit board, an interposer,another semiconductor device, or leads. Contact areas of the carriersubstrate correspond to rerouted bond pads of the first, reroutedsemiconductor device, as well as to bond pads of the secondsemiconductor device. Discrete conductive elements, such as wire bonds,conductive tape-automated bond (TAB) elements carried by a dielectricsubstrate, or leads, may electrically connect bond pads of the first andsecond semiconductor devices to corresponding contact areas of a carriersubstrate.

Methods for designing rerouting elements are also within the scope ofthe present invention, as are methods for forming rerouted semiconductordevices, methods for assembling semiconductor devices in stackedrelation, and methods for packaging semiconductor devices.

Other features and advantages of the present invention will becomeapparent to those of ordinary skill in the art through consideration ofthe ensuing description, the accompanying drawings, and the appendedclaims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, which illustrate exemplary embodiments of variousaspects of the present invention:

FIG. 1 is a top view of an exemplary embodiment of rerouting elementincorporating teachings of the present invention;

FIG. 2 is a cross-section taken along line 2-2 of FIG. 1;

FIG. 3 is a top view of an assembly including the rerouting element ofFIGS. 1 and 2 and a semiconductor device with centrally located bondpads;

FIG. 4 is a cross-section taken along line 4-4 of FIG. 3;

FIG. 4A is a cross-sectional representation depicting another exemplaryembodiment of rerouting element, which is configured to substantiallycover a surface of a semiconductor device;

FIG. 5 is a side view of a stacked two-semiconductor device assemblyincluding semiconductor devices and rerouting elements of the typeillustrated in FIG. 4A;

FIG. 6 is a side view of an exemplary stacked arrangement of an assemblythat includes three semiconductor devices and rerouting elements of thetype illustrated in FIG. 4A;

FIG. 7 is a side view of another exemplary stacked arrangement of anassembly that includes three semiconductor devices and reroutingelements of the type illustrated in FIG. 4A;

FIG. 8 is a cross-sectional representation of a multi-chip moduleincluding the assembly of FIG. 5, a carrier substrate, an encapsulant,and external connective elements;

FIG. 9 is a top view of another exemplary embodiment of reroutingelement, which is configured to reroute peripherally located bond padsof a semiconductor device toward a single edge or two adjacent edges ofthe semiconductor device;

FIG. 10 is a top view of yet another exemplary embodiment of reroutingelement;

FIG. 11 is a top view of a stacked assembly including semiconductordevices and rerouting elements of the type depicted in FIG. 10;

FIG. 12 depicts the assembly of FIG. 11 secured and electricallyconnected to a carrier substrate; and

FIG. 13 is a cross-sectional representation of a multi-chip moduleincluding the assembly of FIG. 12, an encapsulant, and externalconnective elements.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 depict an exemplary embodiment of a rerouting element 40,which is configured to be disposed on an active surface 32 of asemiconductor device 30 (FIGS. 3 and 4) and to reroute bond pad 34locations of semiconductor device 30. Rerouting element 40 includes abase substrate 41 with a top side 42 and a bottom side 43, electricallyconductive vias 44 exposed at bottom side 43 and extending toward topside 42, at least partially through base substrate 41, conductive traces45 carried by base substrate 41 and extending from a correspondingelectrically conductive via 44 toward an outer periphery 46 of basesubstrate 41 to contact pads 47 located adjacent to outer periphery 46of base substrate 41 and exposed at top side 42 thereof. While contactpads 47 are depicted as being located adjacent to a single peripheraledge 46 a of base substrate 41, rerouting elements that include contactpads positioned proximate to two adjacent edges of the base substratesthereof are also within the scope of the present invention.

As base substrate 41 of rerouting element 40 is configured to bedisposed on active surface 32 of semiconductor device 30, base substrate41 need only have sufficient dimensions to cover active surface 32 or aportion thereof.

Base substrate 41 may be formed from a dielectric material, such as anonconductive polymer (e.g., polyimide). In addition, base substrate 41may comprise a flexible, relatively thin, substantially planar member,enabling base substrate 41 to minimize package height and, as desired,to conform somewhat to surfaces that are located at different elevations(e.g., the different elevations of a multi-chip module). It is currentlypreferred that base substrate 41 comprise a flex tape, such as that usedto fabricate a TAB element. Alternatively, base substrate 41 maycomprise a substantially planar member formed from any other dielectricmaterial (e.g., glass, ceramic, etc.) or at least partiallydielectric-coated semiconductor material or even a dielectric-coatedmetal if heat transfer is to be facilitated.

As an example and not to limit the scope of the present invention,electrically conductive vias 44 may comprise conductive bumps, such asbumps of solder, gold, or another suitable metal or metal alloy.Alternatively, conductive vias 44 may comprise columns, pillars, orother structures that are formed from a suitable, electricallyconductive material, such as a conductive or conductor-filled epoxy oran anisotropically conductive (z-axis) elastomer.

Conductive traces 45 may, by way of example only, be formed from a lowelectrical resistance, electrically conductive material, such asaluminum or copper.

Each conductive trace 45 of rerouting element 40 may extend eitherinternally through or externally across base substrate 41.Alternatively, each conductive trace 45 may include one or moreinternally and externally carried portions. While it is preferred thatany external portions of conductive traces 45 be carried on top side 42of base substrate 41, conductive traces 45 or portions thereof may alsobe exposed to bottom side 43.

While conductive traces 45 may be nonlinear, some or all of conductivetraces 45 may alternatively provide the shortest possible path lengthbetween a corresponding electrically conductive via 44 and contact pad47. Accordingly, substantially straight conductive traces 45 are withinthe scope of the present invention. As another option, conductive traces45 may be of substantially the same length to match impedance and signalspeed.

Adjacent conductive traces 45 are preferably electrically isolated fromone another, either by being spaced apart from one another on basesubstrate 41 or by the material of base substrate 41 locatedtherebetween. In addition, conductive traces 45 may be positioned,oriented, and spaced on base substrate 41 relative to one another insuch a manner as to reduce or eliminate any electrical interferencetherebetween. Conductive traces 45 of rerouting element 40 may beparallel or nonparallel to one another.

Contact pads 47 are carried upon either top side 42 of base substrate 41at or adjacent to a peripheral edge 46 a thereof or on peripheral edge46 a. Such positioning of contact pads 47 facilitates access thereto byequipment that will secure discrete conductive elements 56 (FIG. 8) tocontact pads 47 (e.g., a wire bonding capillary, ultrasonic bondingequipment, thermocompression bonding equipment, etc.).

Portions of base substrate 41 that underlie conductive traces 45 mayelectrically isolate conductive traces 45 from an active surface 32 ofan underlying semiconductor device 30 (FIGS. 3 and 4). Alternatively, orin addition, at least portions of bottom side 43 of base substrate 41may be coated with an adhesive material 48, such as a thermoset resin ora pressure-sensitive adhesive. Such a coating of adhesive material 48may facilitate securing of rerouting element 40 to an active surface 32of a semiconductor device 30 (FIGS. 3 and 4). Adhesive material 48 mayalso electrically insulate conductive traces 45 and contact pads 47 fromunderlying features of a semiconductor device 30 upon which reroutingelement 40 is positioned, or provide an additional insulative layer orstandoff distance that decreases or eliminates any electricalinterference that may occur between semiconductor device 30 andconductive traces 45 or contact pads 47.

A rerouted semiconductor device 20 that includes a rerouting element 40and a semiconductor device 30 is illustrated in FIGS. 3 and 4.Semiconductor device 30 includes centrally located bond pads 34 onactive surface 32 thereof. As depicted, bond pads 34 are arranged in asubstantially linear manner, in a so-called leads-over-chip (LOC)configuration.

Rerouting element 40 is positioned on active surface 32, over bond pads34 and adjacent to at least one peripheral edge 36 of semiconductordevice 30. Rerouting element 40 may be secured to active surface 32 byway of adhesive material 48.

Electrically conductive vias 44 of rerouting element 40, which arepositioned adjacent a peripheral edge 46 a of base substrate 41, alignwith corresponding bond pads 34 so that electrical connections may beestablished therewith. By way of example only, electrical connectionsand, thus, electrical communication may be established by way ofphysical contact between electrically conductive vias 44 and theircorresponding bond pads 34. Alternatively, discrete connective elementsformed from a conductive material, such as solder, conductive orconductor-filled epoxy, or anisotropically conductive (z-axis)elastomer, may physically and electrically connect each electricallyconductive via 44 of rerouting element 40 to its corresponding bond pad34 of semiconductor device 30.

Upon positioning rerouting element 40 on active surface 32 and aligningelectrically conductive vias 44 with their corresponding bond pads 34,contact pads 47 of rerouting element 40 are located adjacent toperipheral edge 36 of semiconductor device 30. Thus, each electricallyconductive via 44, along with its corresponding conductive trace 45 andcontact pad 47, reroutes a corresponding bond pad 34 on active surface32 of semiconductor device 30 from a central location to the moreperipheral location at which contact pad 47 is positioned.

FIG. 4A depicts a variation of rerouted semiconductor device 20′, whichincludes a semiconductor device 30 and a variation of rerouting element40′ on active surface 32 thereof. Rerouting element 40′ includes a basesubstrate 41′ that is sized to be superimposed over a greater area ofactive surface 32 than base substrate 41 of rerouting element 40. Asshown, electrically conductive vias 44′ of rerouting element 40′ arepositioned centrally with respect to base substrate 41′, rather thanadjacent to a peripheral edge 46′ thereof. As will be seen from theensuing description, a rerouting element 40′ of this configuration maysupport another semiconductor device 30 superimposed thereover withgreater stability than rerouting element 40, particularly if basesubstrates 41 and 41′ are fairly thick.

Referring now to FIG. 5, a semiconductor device assembly 10 is shownthat includes two rerouted semiconductor devices 20 a′, 20 b′ instacked, or superimposed, relation. As shown, the upper semiconductordevice 20 b′ is staggered relative to the next-lower reroutedsemiconductor device 20 a′, with contact pads 47 of reroutedsemiconductor device 20 a′ being exposed laterally beyond an outerperiphery 36 of semiconductor device 30 b and, thus, beyond an outerperiphery of rerouted semiconductor device 20 b′.

A back side 33 of the semiconductor device 30 b of the upper reroutedsemiconductor device 20 b′ is spaced apart from active surface 32 of thesemiconductor device 30 a of the lower rerouted semiconductor device 20a′, at least in part, by way of rerouting element 40′. Back side 33 ofsemiconductor device 30 b is secured to a top side 42′ of base substrate41′ and, thus, of rerouting element 40′ by way of dielectric adhesivematerial 49 therebetween.

Electrically conductive vias 44 and any externally carried portions ofconductive traces 45 that extend between the adjacent semiconductordevices 30 a and 30 b may be electrically isolated from back side 33 ofthe upper semiconductor device 30 b by way of dielectric adhesivematerial 49 that secures back side 33 to top side 42′. Alternatively,the material of base substrate 41′ may electrically isolate electricallyconductive vias 44 and conductive traces 45 from back side 33 whenelectrically conductive vias 44 do not extend fully through thethickness of base substrate 41′ and the portions of conductive traces 45that are located between semiconductor devices 30 a and 30 b are carriedinternally by base substrate 41′. Of course, electrically conductivevias 44 and conductive traces 45 may also be electrically isolated fromback side 33 of the next-higher semiconductor device 30 b by anycombination of dielectric adhesive material 49 and base substrate 41′material.

FIGS. 6 and 7 illustrate stacked semiconductor device assemblies 10′ and10″, respectively, which include more than two rerouted semiconductordevices 20′. In FIG. 6, contact pads 47 of each rerouted semiconductordevice 20 a′, 20 b′, 20 c′ are positioned adjacent the same peripheraledge 16 a′ of assembly 10′. Rerouted semiconductor devices 20 a′, 20 b′,20 c′ are progressively staggered to facilitate the securing of discreteconductive elements 56 (FIG. 8) to each contact pad 47.

Assembly 10″ of FIG. 7 includes rerouted semiconductor devices 20 a′, 20b′, 20 c′ that are arranged with contact pads 47 of the upper and lowerrerouted semiconductor devices 20 c′ and 20 a′ being positioned adjacentto the same peripheral edge 16 a″ of assembly 10″ and contact pads 47 ofthe central rerouted semiconductor device 20 b′ being positionedadjacent to an opposite peripheral edge 16 b″ of assembly 10″. Tofacilitate electrical connection to contact pads 47 of each reroutedsemiconductor device 20 a′, 20 b′, 20 c′, rerouted semiconductor devices20 a′, 20 b′, 20 c′ are arranged in repeating staggered relation. Statedanother way, while rerouted semiconductor device 20 b′ is only partiallysuperimposed over rerouted semiconductor device 20 a′, reroutedsemiconductor device 20 c′ is completely superimposed over reroutedsemiconductor device 20 a′. The distance between contact pads 47 of thelowermost rerouted semiconductor device 20 a′ and back side 33 ofsemiconductor device 30 c of the uppermost rerouted semiconductor device20 c′ may be sufficient to provide access by discrete conductive elementpositioning or forming equipment (e.g., a wire bonding capillary,thermocompression bonding equipment, ultrasonic bonding equipment, etc.)to contact pads 47 of rerouted semiconductor device 20 a′. In any event,the spacing between top side 42′ of the base substrate 41′ of reroutingelement 40′ of rerouted semiconductor device 20 a′ and back side 33 ofsemiconductor device 30 c of rerouted semiconductor device 20 c′ issufficient for discrete conductive elements 56 (FIG. 8) to extendtherebetween.

As shown in FIG. 8, a semiconductor device package 50 including assembly10 is depicted. In package 50, rerouted semiconductor device 20 a′ ofassembly 10 is secured to a carrier substrate 52, such as the depictedcircuit board, an interposer, another semiconductor device, or leads ofa lead frame. Contact pads 47 of rerouted semiconductor devices 20 a′and 20 b′ are electrically connected to, or communicate with,corresponding contact areas 54 of carrier substrate 52 by way ofdiscrete conductive elements 56, such as the depicted bond wires,conductive traces carried upon a flexible dielectric substrate to form aTAB element, thermocompression or ultrasonically bonded leads, or thelike, that extend therebetween. Package 50 may also include a protectiveencapsulant 58 that may surround rerouted semiconductor devices 20 a′and 20 b′, discrete conductive elements 56, and portions of carriersubstrate 52 located adjacent to rerouted semiconductor device 20 a′. Byway of example only, protective encapsulant 58 may comprise a moldedstructure (e.g., a pot molded or transfer molded structure) or aso-called “glob top” type structure of viscous dielectric material.

FIG. 9 depicts another example of a routing element 40″ for use with asemiconductor device that includes bond pads positioned adjacent to morethan one peripheral edge thereof to reroute the locations of the bondpads of such a semiconductor device to locations adjacent one peripheraledge or two adjacent peripheral edges of the semiconductor device.

Rerouting element 40″ is configured similarly to rerouting elements 40and 40′, but includes electrically conductive vias 44″ that arepositioned adjacent an outer periphery 46″ of base substrate 41″ atlocations on top side 42″ thereof that correspond to the locations ofbond pads on the active surface of the semiconductor device over whichrerouting element 40″ is to be positioned. Of course, conductive traces45″ of rerouting element 40″ extend from corresponding electricallyconductive vias 44″ to contact pads 47″ positioned adjacent either oneperipheral edge 46 b″ or two adjacent peripheral edges 46 a″, 46 b″ ofbase substrate 41″.

A rerouted semiconductor device including rerouting element 40″ may beassembled with one or more other rerouted semiconductor devices 20″,20′, or other semiconductor devices that include bond pads that are eachpositioned adjacent to either a single peripheral edge thereof or twoadjacent peripheral edges thereof in a manner similar to the assembliesdepicted in FIGS. 5-7.

As rerouting element 40″ reroutes bond pads from locations that areadjacent to three or four peripheral edges thereof to locations that areadjacent to one or two peripheral edges thereof, stacked assemblies ofdecreased height may be achieved when rerouting element 40″ is used.This can be seen in FIGS. 11-13, which, although described in terms ofrerouting element 40′″ of FIG. 10, depict an exemplary staggeredstacking arrangement that can be used when a rerouting element 40″ withcontact pads 47″ adjacent to one or two peripheral edges 46 a″, 46 b″thereof is used with a semiconductor device that includes bond padsarranged around three or four peripheral edges thereof.

Turning now to FIG. 10, another exemplary embodiment of reroutingelement 40′″ is depicted. Rerouting element 40′″ includes a basesubstrate 41′″, electrically conductive vias 44′″, conductive traces45′″ and contact pads 47′″ that are substantially the same as thecorresponding elements of rerouting elements 40 and 40′ (FIGS. 1-8).Again, electrically conductive vias 44′″ are positioned correspondinglyto bond pads 34 positioned centrally on an active surface 32 of asemiconductor device 30 over which rerouting element 40′″ is to bepositioned. However, contact pads 47′″ of rerouting element 40′″ arepositioned adjacent to more than one peripheral edge 46′″ of basesubstrate 41′″.

Rerouted semiconductor devices 20′″ formed by assembling reroutingelements 40′″ with complementarily configured semiconductor devices 30may be used in any appropriate, known type of semiconductor deviceassembly or multi-chip module, such as in the stacked assembly 10′″depicted in FIG. 11.

FIG. 12 depicts stacked assembly 10′″ secured to a carrier substrate52′″ in an exemplary fashion. Although carrier substrate 52′″ is shownas comprising an interposer, it may alternatively be in the form of acircuit board, a lead frame, another semiconductor device, or any othersuitable substrate known in the art. Contact areas 54′″ of carriersubstrate 52′″ may communicate with corresponding contact pads 47′″ ofeach rerouted semiconductor device 20′″ or other semiconductor device ofassembly 10′″ by way of discrete conductive elements 56 (e.g., bondwires, TAB elements, thermocompression or ultrasonically bonded leads,etc.) placed or formed therebetween. Of course, it is preferred thatdiscrete conductive elements 56 be electrically isolated from oneanother, as well as from any other structures (e.g., semiconductordevices 30) over which they extend.

As shown in FIG. 13, stacked assembly 10′″ and carrier substrate 52′″may be incorporated into a package 50′″. Package 50′″ may also include aprotective encapsulant 58′″ that covers at least portions of eachrerouted semiconductor device 20′″ or other semiconductor device ofassembly 10′″, discrete conductive elements 56, and regions of carriersubstrate 52′″ that are located proximate an outer periphery of assembly10′″. Protective encapsulant 58′″ may comprise a glob top typeencapsulant, as depicted, or any other known type of semiconductordevice encapsulant, such as a pot molded encapsulant or a transfermolded encapsulant.

Referring again to FIGS. 1-4, a method for designing a rerouting element40 that incorporates teachings of the present invention includesidentifying a semiconductor device 30 with bond pads 34 to be rerouted,as well as determining the locations of rerouting element 40 to whichbond pads 34 are to be rerouted. Accordingly, the design method includesconfiguring electrically conductive vias 44 of rerouting element 40 tobe positioned correspondingly to bond pads 34 of the identifiedsemiconductor device 30. Conductive traces 45 of rerouting element 40are configured to extend from the locations of correspondingelectrically conductive vias 44, with which conductive traces 45communicate, to a desired, reroute location on a base substrate 41 ofrerouting element 40. In addition, contact pads 47 are configured at thedesired, reroute locations of base substrate 41.

Returning reference to FIGS. 5 and 8, an assembly method incorporatingteachings of the present invention includes providing a carriersubstrate 52 and securing a first rerouted semiconductor device 20 a′ tocarrier substrate 52. Rerouted semiconductor device 20 a′ may be securedto carrier substrate 52 by way of an adhesive material 53 (e.g., apressure sensitive adhesive, a thermoset resin, a thermoplasticelastomer, etc.) disposed between superimposed regions of reroutedsemiconductor device 20 a′ and carrier substrate 52.

A second semiconductor device, such as the depicted reroutedsemiconductor device 20 b′ or any other semiconductor device includinginput/output pads that are arranged in a fashion that may be used instacked multi-chip modules, may be positioned over reroutedsemiconductor device 20 a′. Rerouted semiconductor device 20 b′ isdepicted as being only partially superimposed over reroutedsemiconductor device 20 a′, with contact pads 47 of the lower reroutedsemiconductor device 20 a′ being exposed beyond an outer periphery 26′of the upper rerouted semiconductor device 20 b′. Alternatively, asdepicted in FIG. 13, the upper semiconductor device may be substantiallysuperimposed over the lower semiconductor device.

Contact pads 47 of each semiconductor device 20 a′, 20 b′ may beelectrically connected to and, thus, electrically communicate withcorresponding contact areas 54 of carrier substrate 52 by forming orpositioning discrete conductive elements 56 between correspondingcontact pads 47 and contact areas 54. Such positioning may be effectedat any time that appropriate discrete conductive element-forming or-positioning equipment may access contact pads 47, including, withoutlimitation, prior to the placement of a second semiconductor device(e.g., rerouted semiconductor device 20 b′) over first reroutedsemiconductor device 20 a′ and after the semiconductor devices (e.g.,rerouted semiconductor devices 20 a′ and 20 b′) have been assembled withone another in stacked relation.

Although the foregoing description contains many specifics, these shouldnot be construed as limiting the scope of the present invention, butmerely as providing illustrations of some exemplary embodiments.Similarly, other embodiments of the invention may be devised which donot depart from the spirit or scope of the present invention. Featuresfrom different embodiments may be employed in combination. The scope ofthe invention is, therefore, indicated and limited only by the appendedclaims and their legal equivalents, rather than by the foregoingdescription. All additions, deletions, and modifications to theinvention, as disclosed herein, which fall within the meaning and scopeof the claims are to be embraced thereby.

1. A semiconductor device assembly, comprising: a first semiconductordie including a surface with a plurality of bond pads located adjacentto at least three peripheral edges of the surface; and a reroutingelement positioned adjacent to a surface of the first semiconductor die,the rerouting element including: a substrate; conductive vias locatedadjacent to at least three peripheral edges of the substrate; conductivetraces including first ends in communication with correspondingconductive vias and second ends adjacent to one peripheral edge or twoadjacent peripheral edges of the substrate; and rerouted bond pads incommunication with the second ends of the conductive traces.
 2. Thesemiconductor device assembly of claim 1, further comprising: a secondsemiconductor die positioned over a portion of the rerouting element,each rerouted bond pad being exposed beyond a periphery of the reroutingelement.
 3. The semiconductor device assembly of claim 1, wherein eachrerouted bond pad is located laterally adjacent to a periphery of thefirst semiconductor die.
 4. The semiconductor device assembly of claim1, wherein each rerouted bond pad is located adjacent to a single edgeof the first semiconductor die.
 5. The semiconductor device assembly ofclaim 1, wherein each rerouted bond pad is located adjacent to one oftwo adjacent edges of the first semiconductor die.
 6. The semiconductordevice assembly of claim 1, further comprising: a carrier substrate. 7.The semiconductor device assembly of claim 6, wherein the firstsemiconductor die is secured to the carrier substrate.
 8. Thesemiconductor device assembly of claim 2, further comprising: anotherrerouting element on a bond pad-bearing surface of the secondsemiconductor die.
 9. The semiconductor device assembly of claim 2,wherein the second semiconductor die is oriented in staggered relationto the first semiconductor die.
 10. The semiconductor device assembly ofclaim 2, wherein the second semiconductor die is smaller than the firstsemiconductor die.
 11. The semiconductor device assembly of claim 2,further comprising: at least one additional semiconductor die positionedover the second semiconductor device.
 12. A rerouting element for usewith a semiconductor device, comprising: a substrate; conductive viaslocated adjacent to at least three peripheral edges of the substrate;conductive traces including first ends in communication withcorresponding conductive vias and second ends adjacent to one peripheraledge or two adjacent peripheral edges of the substrate; and contact padsin communication with the second ends of the conductive traces.
 13. Thererouting element of claim 12, wherein the conductive vias are locatedadjacent to three peripheral edges of the substrate.
 14. The reroutingelement of claim 13, wherein each contact pad is located adjacent toanother, single peripheral edge of the substrate.
 15. The reroutingelement of claim 12, wherein each conductive via is located so as toalign with a corresponding, peripherally located bond pad of thesemiconductor device upon assembly of the rerouting element with thesemiconductor device.